1. Field of Invention
The field of the present invention relates to packet switched distribution of video and television over networks.
2. Description of the Related Art
The distinction between content available on TVs and computers used to be reasonably clear. TVs delivered selectable television channels or video on demand from established content providers on large dedicated displays with integrated tuning. Computers delivered the Internet with static pages and short video clips on relatively small displays. A loosely organized suite of protocols differing by region and provider and identified as Internet Protocol TV (IPTV) is gradually blurring this distinction. IPTV delivers traditional selectable live TV and stored VOD content from traditional content providers in a packet switched format over the Internet to computers or TVs. In the United States AT&T offers such IPTV services under their U-Verse brand. To reduce network traffic, the video content is heavily compressed using various Motion Picture Experts Group (MPEG) codecs the most recent of which is H.264 (MPEG-4). The compressed video is parsed into packets and encapsulated for transport over the Internet. To reduce bandwidth associated with routing the same packets to multiple computers or TV's viewing the same content from a single head end multicast protocols such as Internet Group Management Protocol (IGMP) and Protocol Independent Multicast (PIM) have been promulgated. These protocols allow intelligent feedback between and operation of distribution nodes across the network, e.g. video head end, router, switches, bridges, broadband access devices and set top boxes. Each compliant distribution node reduces redundancy in upstream packets to viewers in the same group and is capable of replicating packets to downstream viewers of the same content.
Current IPTV systems require a significant investment in delivery infrastructure, and the first entrants into the market appear to be Telco's seeking to expand the number of customer services available over a single broadband connection, e.g. a subscriber line. For marketing purposes such services are identified as ‘triple play’ if they include: wired telephone, TV, and high speed Internet or ‘quadruple play’ if they also offer wireless mobile phone access within the home.
The chief concerns among prospective customers of these Telco offerings as regards the TV or VOD portion of the offering are picture quality and latency. Latency corresponds to the time delay between the selection of a new channel, i.e. TV or VOD, and the viewing of that selection in the home or residence.
What is needed is an IPTV system with improved picture quality and reduced latency.